Method of and apparatus for cutting blanks from sheet material



Jan. 6, 1942. R. w. CUMMINGS 2,268,856

. METHOD OF AND APPARATUS FOR CUTTING BLANKS FROM SHEET MATERIAL Filed Jan. 4, 1941 Patented Jan. 6, 1942 METHOD OF AND APPARATUSFOR CUTTING- BLANKSiFROM SHEET MATERIAL Roy W. Cummings, Beverly, Mass, assignor to I United Shoe Machinery Corporatfon,.- Fl'emington, N; J., a corporation of. NewJersey NT OFFICE Application January 4, maternal-No. 373,120

Claims. 01; 16.4- 2e).

This invention relates to the cutting of blanks from sheet material and is herein illustrated in relation to the cutting of shoe part blanks; such as box toes, from layers of fabricor other sheet will produce aplurality of closely nested cuts.

Preferably, some of the gages are arranged to engage a portion of' the .material in a. previously made cut for'locating the die with its cutting edge close. to the. cut in such a way that there material. 5 is little wasteof material.

In producing shoe part blanks, such: as box These. and other features ofv the invention are toes, counters and other parts which go into a disclosedtin the. following specification and, in shoe, use has been commonly made of a die theaccompanyingdrawing, and are pointed out which is forced through. one or more layers of in theclaims. sheet material to form the. blanks, it being, cus- In the. drawing,. tomary to'locate the die in successive dieing-out Fig. .lisaiperspective view of a die constructed operations by hand in such a way that, during in accordancewith my invention; each operation, the die is positioned closely ad- 2." is a plan; view illustrating mechanism jacent to a previous cut'in order to utilize. all for holding the work upon a support and-for the material possible to avoid waste. It is an the die across thework;' object of the present inventionto provide. an Fig. 3 is a. perspective view of a portion of the improved method of cutting sheet material, in mechanism shown in Fig.2; j which the dies are so placed as to reduce the Fig. 4 is aside view; partly in section; showing amount of waste of material to a minimum; one of the gages on the die in work-engaging To this end and as illustrated, one feature of position; and s the invention comprises a method which consists Fig. 5 is a side elevation, partly in section, of a in providing a die having a plurality of workwork gage member. engaging members and a guide for locating the As illustrated in Fig. 2, theinvention contemclie widthwise of the material, successively locatplatesthecutting of box toeblanks from a pluing the die along the guide widthwise of the marality of layers of sheetmateri'al l0, locatedupon terial, utilizing one set of gage members, pera work support-l2, successive rows of nested cuts forming a series .of cuts in a row widthwise of being made in the material by' means of a die the material to produce blanks, shifting the mal4, which can be driven through the material terial relatively to the guide; successivelylocating either by a hand mallet or a reciprocating presser the die widthwise of the material along the guide member (not shown), the-diebei-ng located in its with other of the gage members in engagement successive positions lengthwise of the material by with the guide to locate the die successively in means of a guide member or straight edge l6. position close to the previous row of cuts made, The die l4 comprises a hollow base member l8 and performing dieing-out operations to form a terminating in a cutting edge 20 corresponding series of cutswidthwise of the material in proin outline to that of a box toe blank, which it is ducing a second row of blanks. Thismethod is desired to produce fromthe sheet material, comadvantageous in that the die is quickly and acmonly fabric. impregnated with stiffening matecuratelylocated in position for forming succesrial. Thedie M is provided with laterally exsi-ve cuts in a row of cuts, as well as in performing tending abutments or plates 2| and 22 having successive rows of cuts such that the material is .four corners, edge portions of which are mautilized to form blanks with only a small amount chined' to form' gaging surfaces 24, '25 and- 26. of waste between the cuts. At the same time, this The surfaces 214 and arev arranged to engage method facilitates the handling of the material the guide. member. 16 in locating the dielengthand the die during the dieing-out operations, en.- wise ofthe material-for various positions of the abling the operator, even though comparatively die transversely of the material. When the-surunskilled', accurately and rapidly to locate the faces 24 at the left hand portion of the die (Fig. die for each cut with a minimum of effort. 1) are in engagement with the guide member,

Another feature of the invention relates to a the. convexly curved portion of the cutting edge die, which, as herein illustrated, comprises a hol- 20 extends to the-right. The reverse is true when low cutting blade provided with gages for locatthe surfaces 25 at the right-hand portion of the ing the die both widthwise and lengthwise of a diev (Fig. 1) are'inengagement with the guide. sheet of material with the cutting edge located These gaging surfaces 24 and '25 thus can be in any one of a plurality of predetermined posiused in. facilitating, thenestingof the cuts, as will tions, such that successive dieing-out operations behereinafterdescribed. The-gagingsurfaces 26 M areadapted to. engage a straight edge2l to locate the die for the initial out along an edge of the material.

The die is provided with two bosses 28, in which are positioned spring-pressed plungers 30 and 32, respectively. These plungers terminate in gage members 34 and 36, which are shaped to correspond to portions of the curvature of the blanks to be cut, and are utilized in locating the die in position for successive cuts. For example, as shown in Figs. 2 and 4, the die is moved between successive cuts in such a manner that the gage 34 is in contact with the wall of the material left by the preceding cut, thus making it possible to locate the die in predetermined position with its cutting edge closely adjacent to the previous cut, but at the same time sufliciently spaced therefrom that the next cut to be made will not overlap the previous one. After one row of cuts has been made across the material, the die is turned end-for-end, and the gage 36 is used to locate the die in successive positions in producing the next row of cuts, this being illustrated at the left-hand portion of Fig. 2, inwhich the gage 36 is shown in successive positions of contact with the corner portion of successive cuts comprising the first row of cuts. Each of the plungers 36 is forced downwardly by a spring 38, downward movement of the plungers being limited by collars 46 pinned thereto and arranged to engage extensions 42 on the abutments 24, such that the gages 34 and 36 can project somewhat below the cutting edge 20 of the die in order to engage the side wall of the material after a blank has been removed therefrom. Rotation of the plungers 30 is prevented by means of downwardly projecting pins 44, which extend through openings in the plates 24.

The guide I6 is in the form of an angle iron, which extends across the work support I2 and has the end portions of its vertical flange 46 cut away, so that the ends of the horizontal flange 41 can project beneath arched brackets 48 secured to the work support I2 by bolts 49. The guide I6 can be located in either of two positions along the work support 12 in engagement with vertical walls of the brackets 48 and secured in position by set screws 56 and 52, which project through the bracket 48, and are rotatable to force the horizontal flange 41 of the guide down upon the work extending thereunder to clamp the same to the work support. The straight edge 21 is secured to the right-hand bracket 48 by screws, one of which is shown at 5|.

The guide I6 carries a bracket 54 slidably mounted for movement along the guide I6 and arranged to be secured in its position by a hand nut 56, the construction being such as to permit adjustment of the bracket along the guide I6, or the removal of the bracket therefrom at such time as the bracket might interfere with operation of the die I4 on the material. The bracket has an elongated slot 58 near the free end thereof through which extends a spindle 66, which carries a gage 62. The gage 62 is normally forced downwardly by a spring 64 and can be adjusted along the slot 58 and locked in position by means of a washer 16 and nut 12.

In order to facilitate the handling of several layers of sheet material, it is desirable to clamp the same together by suitable means, such as C- clamps 14. A straight edge 16 is arranged to be engaged by side edges of the material to locate the same transversely of the work support I2.

I In carrying out my method, several-clamped layers of sheet material In from a "roll (not shown) are brought forwardly over the work support I2 until the forward edge portions of the layers extend slightly beyond the gage 62, the guide I6 at this time being in its forward position, as shown in dotted lines in Fig. 2, and the guide is clamped down upon the material by screws 52. The die I4 is then placed upon the material with the gaging surfaces 24 in engagement with the vertical flange 46 of the guide I6, the die being located at the extreme right-hand portion of the material with a gaging surface 26 in contact with the straight edge 21. The die is then subjected to a pressure-applying operation, such as a blow of a hand mallet or a mechanically operated presser member, to force the die through the material. The die is then moved transversely with the gage members 24 again in contact with the guide I6, and the die is located relatively to the first cut by means of the gage member 34, which contacts with the side wall of that cut. This operation is repeated until a row of cuts is produced across the full width of the material. The screws 52 are then released, and the guide member I6 is moved rearwardly until its horizontal flange engages the bracket 48 and the screws 56 are then tightened to clamp the material down upon the work support. The die is then turned end-for-end and positioned With the gage members 25 in engagement with the guide I6 and with the gage 36 located in contact with the wall of the last out made in the first row of cuts. The pressure is then applied to the die to produce the first cut of the second row of cuts, after which the die is successively moved into positions with the gage 36 in contact with successive cuts of the first row of cuts, and pressure-applying operations are made until a series of cuts are made which extend across the full width of the material to form the second row of cuts. This cycle of operations is repeated until a sufficient number of blanks is produced, or the entire length of the material is utilized, the material being pulled forwardly immediately prior to the formation of each odd row of cuts and the material being located in position lengthwise by engagement of the gage 62 with the edge of the material at the corner of a cut in the immediately preceding row.

Having described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. The method of cutting blanks from sheet material which consists in providing a straight edge and a die having gage members for engaging the straight edge and other gage members for engaging a cut portion of the work, positioning the straight edge upon sheet material located upon a work support, performing a series of cutting operations with the die successively spaced along the straight edge by a predetermined distance from a cut portion of the material formed by the preceding cut, shifting the straight edge through a predetermined distance laterally of the first row of cuts produced, and performing another series of cutting operations with the die successively located in nested position relatively to the cuts of the first row of cuts and spaced by predetermined distances along the straight edge.

2. The method of cutting blanks from sheet material which consists in providing a straight edge and a die having a plurality of gage members, placing the straight edge upon sheet material located upon-a work support, performing a series of cutting operations with the die in engagement with the straight edge, shifting the die laterally after eachcutting operation and locating it in position adjacent to the previous cut by contact of one of the gage members with the wall of the material formed by the previous cut, shifting the straight edge by a predetermined distance laterally of the row of cuts produced, performing a second series of cutting operations with the die in engagement with the straight edge, shifting the die laterally after each operation, and locating it in position adjacent to a previous cut in the second row of cuts and to cuts of the first row of cuts by engagement of another of the gage members with the edges of material formed by a previous cut, thus to produce a plurality of cuts in successive rows in closely nested relation.

3. For use in apparatus for cutting blanks from sheet material, a straight edge, and a freely movable cutting die having gage members for engaging the straight edge to locate the die along the material in one direction and having a gage adapted to engage a previously cut portion of the work for locating the die along the material in another direction.

4. For use in apparatus for cutting blanks from sheet material, the combination of a straight edge, and a die having a gage member for engaging the straight edge to position the die for locating the die transversely of the sheet material to be operated upon, and a plurality of gage members carried by the die, each of which is adapted to engage a cut portion of the work formed by a previous cutting operation for spacing the die a predetermined distance from a preceding cut, the gage members being located relatively to the cutting edge of the die and to the abutments such that when the gage members are in engagement with a straight edge the die can be located by means of the abutments in nested relation to previously formed cuts.

ROY W. CUMMINGS. 

